Let's say that I live in my own world, with 20 inhabitants.

I own a firm called mc Donald's. ( my people purchase food there of course).

Each income to mc Donald's gets into the firm bank.

McDonald's is also tracking profit each hour , day, week and month.

As McDonald's owner , I will be able to take out any of the profit whenever I want to.

Here comes the question

Let's say I want to make mc Donald's a stock market , where my inhabitants can buy and sell stocks on mc Donald's firm.

How can I accomplish this ? How and what algorithms can I use to do stock price changes to make it appear to be working like how real stock firms works ?

How many stocks should I allow the firm to have ?

Any suggestions or spoon feed on how I can make this mc Donald's function like a stock market in itself ?

What will be needed for a price drop / increase on the stock's price ?